Virtually all animals are both predators (in some sense) and potential prey for other animals. Understanding the behavioral implications of this simple truism has been a major focus of ecologically-based behavioral research over the past 10 to 15 years. This research has led to considerable insight into the nature of animal decision-making, and has enhanced the ability of biologists to predict animal behavior under natural conditions. Research on anti-predatory behavior has also yielded much insight into both the evolution of behavior and the nature of large-scale ecological systems. Dr. Lima's research follows in this tradition and focuses specifically on a prominent area in anti-predatory behavior: the detection of predators by socially-feeding animals. A great deal of work in this area indicates that animals somehow coordinate their anti-predatory vigilance (that is, alert behavior), and, in essence, detect predatory attack as a socially-integrated unit. This work has many ecological and evolutionary implications, particularly for the evolution of cooperative behavior in animals. However, Dr. Lima's recent NSF-funded research reveals that dark-eyed juncos do not coordinate their vigilance, nor do they detect attack as an integrated unit. These discoveries raise several interesting questions, which Dr. Lima will now pursue. He will see if his anomalous findings hold across several bird species. Dr. Lima also will investigate how flock members find out that a predator has been detected by other individuals; previous work indicates that there is very little direct transfer of information within the flock. This research will indicate whether or not a major reassessment is needed in this important and long-standing area in the study of anti- predatory behavior.